Category Archives: Security

The TSA’s Approach to Threat Modeling

Posted on by

“I understand people’s frustrations, and what I’ve said to the TSA is that you have to constantly refine and measure whether what we’re doing is the only way to assure the American people’s safety. And you also have to think through are there other ways of doing it that are less intrusive,” Obama said.

“But at this point, TSA in consultation with counterterrorism experts have indicated to me that the procedures that they have been putting in place are the only ones right now that they consider to be effective against the kind of threat that we saw in the Christmas Day bombing.” (“Obama: TSA pat-downs frustrating but necessary“)

I’ve spent the last several years developing tools, techniques, methodologies and processes for software threat modeling. I’ve taught thousands of people more effective ways to threat model. I’ve released tools for threat modeling, and even a game to help people learn to threat model. (I should note here that I am not speaking for my employer, and I’m now focused on other problems at work.) However, while I worked on software threat modeling, not terror threat modeling, the President’s statement concerns me. Normally, he’s a precise speaker, and so when he says “effective against the kind of threat that we saw in the Christmas Day bombing,” I worry.

In particular, the statement betrays a horrific backwards bias. The right question to ask is “will this mitigation protect the system against the attack and predictable improvements?” The answer is obviously “no.” TSA has smart people working there, why are they letting that be the headline question?

The problems are obvious. For example, in a Flyertalk thread, Connie asks: “If drug mules swallow drugs and fly, can’t terrorists swallow explosive devices?” and see also “New threat to travellers from al-Qaeda ‘keister bomb’.”

Half of getting the right answer is asking the right questions. If the question the President is hearing is “what can we do to protect against the threat that we saw in the Christmas day bombing (attempt)” then there are three possible interpretations. First is that the right question is being asked at a technical level, and the wrong question is being asked at the top. Second, the wrong questions are being asked up and down the line. Third is that the wrong question is being asked at the top, but it’s the right question for a TSA Administrator who wants to be able to testify before Congress that “everything possible was done.”

I’ve said before and I’ll say again, there are lots of possible approaches to threat modeling, and they all involve tradeoffs. I’ve commented that much of the problem is the unmeetable demands TSA labors under, and suggested fixes. If TSA is trading planned responses to Congress for effective security, I think Congress ought to be asking better questions. I’ll suggest “how do you model future threats?” as an excellent place to start.

Continuing on from there, an effective systematic approach would involve diagramming the air transport system, and ensuring that everyone and everything who gets to the plane without being authorized to be on the flight deck goes through reasonable and minimal searches under the Constitution, which are used solely for flight security. Right now, there’s discrepancies in catering and other servicing of the planes, there’s issues with cargo screening, etc.

These issues are getting exposed by the red teaming which happens, but that doesn’t lead to a systematic set of balanced defenses.

As long as the President is asking “Is this effective against the kind of threat that we saw in the Christmas Day bombing?” we’ll know that the right threat models aren’t making it to the top.

The 1st Software And Usable Security Aligned for Good Engineering (SAUSAGE) Workshop

Posted on by

National Institute of Standards and Technology
Gaithersburg, MD USA
April 5-6, 2011

Call for Participation

The field of usable security has gained significant traction in recent years, evidenced by the annual presentation of usability papers at the top security conferences, and security papers at the top human-computer interaction (HCI) conferences. Evidence is growing that significant security vulnerabilities are often caused by security designers’ failure to account for human factors. Despite growing attention to the issue, these problems are likely to continue until the underlying development processes address usable security.

See http://www.thei3p.org/events/sausage2011.html for more details.

“Towards Better Usability, Security and Privacy of Information Technology”

Posted on by

“Towards Better Usability, Security and Privacy of Information Technology” is a great survey of the state of usable security and privacy:

Usability has emerged as a significant issue in ensuring the security and privacy of computer systems. More-usable security can help avoid the inadvertent (or even deliberate) undermining of security by users. Indeed, without sufficient usability to accomplish tasks efficiently and with less effort, users will often tend to bypass security features. A small but growing community of researchers, with roots in such fields as human-computer interaction, psychology, and computer security, has been conducting research in this area.

Regardless of how familiar you are with usable security, this report is a worthwhile read.

Grope-a-thon: Today’s TSA roundup

Posted on by

Quantum Crypto is Quantum Backdoored, But It’s Not a Problem

Posted on by

Nature reports that Quantum Cryptography has been completely broken in “Hackers blind quantum cryptographers.” Researcher Vadim Makarov of the Norwegian University of Science and Technology

constructed an attack on a quantum cryptography system that “gave 100% knowledge of the key, with zero disturbance to the system,” as Makarov put it.

There have been other attacks on quantum cryptography, but this is the first in which there is no indication that the key has been stolen. In those attacks, the operator of the system would see the transmission error rate go up, but in Makarov’s attack, the operator sees nothing. In short, they are completely, utterly defeated. The attacker gets everything with impunity.

As usual, the quantum crypto crowd doesn’t see that a 100% loss of key with no inkling of the loss is a problem. Makarov himself said to Nature, “If you want state-of-the-art security, quantum cryptography is still the best place to go.”

Perhaps the kicker is this in Nature’s article:

Ribordy [CEO of ID Quantique] and Zavriyev [Director of R&D at MagiQ] stress that the open versions of their systems that are sold to university researchers are not the same as those sold for security purposes, which contain extra layers of protection. For instance, the fully commercial versions of IDQ’s system also use classical cryptographic techniques as a safety net, says Ribordy.

Huh? We can trust commercial versions of quantum crypto because it uses classical crypto as a safety net? That’s saying that the quantum coolness is really just icing over a VPN. Isn’t it? Am I missing something?

Now it’s time for a rant. Quantum cryptography is really, really cool technology, but the whole point of it is, well, security, and if the state of the art is that the system is breakable, then the art is in a sorry state. It’s a state of being a research toy, not a real security system.

The whole point of quantum crypto is that it isn’t even really crypto. It’s communications that can’t be eavesdropped on. It’s a magical tour-de-force of science and technology. But if it can be silently thwarted, it’s no good. If there is no way that it can be tested to be good, it’s no good. Moreover, the latter is more important than anything else.

For quantum crypto to be viable and trusted, we have to have some way that we know that the boxes were designed and manufactured in such a way that we can be confident that there’s no silent quantum backdoor in the box, then it has no value. You might as well just get a VPN router from the usual suspects and be done with it. If you’re really paranoid, just lay down some glass fiber and put it in a conduit.

Quantum information science as a discipline needs to start taking security seriously. It can’t just brush off a break of this magnitude, and remain credible. Come on, at least admit this is serious and has to be reflected in the manufacturing and testing. Come up with countermeasures, something.

Hacker Hide and Seek

Posted on by

Core Security Ariel Waissbein has been building security games for a while now. He was They were kind enough to send a copy of his their “Exploit” game after I released Elevation of Privilege. [Update: I had confused Ariel Futoransky and Ariel Waissbein, because Waissbein wrote the blog post. Sorry!] At Defcon, he and his colleagues will be running a more capture-the-flag sort of game, titled “Hide and seek the backdoor:”

For starters, a backdoor is said to be a piece of code intentionally added to a program to grant remote control of the program — or the host that runs it – to its author, that at the same time remains difficult to detect by anybody else.

But this last aspect of the definition actually limits its usefulness, as it implies that the validity of the backdoor’s existence is contingent upon the victim’s failure to detect it. It does not provide any clue at all into how to create or detect a backdoor successfully.

…

A few years ago, the CoreTex team did an internal experiment at Core and designed the Backdoor Hiding Game, which mimics the old game Dictionary. In this new game, the game master provides a description of the functionalities of a program, together with the setting where it runs, and the players must then develop programs that fulfill these functionalities and have a backdoor. The game master then mixes all these programs with one that he developed and has no backdoors, and gives these to the players. Then, the players must audit all the programs and pick the benign one.

First, I think this is great, and I look forward to seeing it. I do have some questions. What elements of the game can we evaluate and how? A general question we can ask is “Is the game for fun or to advance the state of the art?” (Both are ok and sometimes it’s unclear until knowledge emerges from the chaos of experimentation.) His blog states “We discovered many new hiding techniques,” which is awesome. Games that are fun and advance the state of the art are very hard to create. It’s a seriously cool achievement.

My next question is, how close is the game to the reality of secure software development? How can we transfer knowledge from one to the other? The rules seem to drive backdoors into most code (assuming they all work, (n-1)/n). That’s unlike reality, with a much higher incidence of backdoors than exist in the wild. I’m assuming that the code will all be custom, and thus short enough to create and audit in a game, which also leads to a higher concentration of backdoors per line of code. That different concentration will reward different techniques from those that could scale to a million lines of code.

More generally, do we know how to evaluate hiding techniques? Do hackers playing a game create the same sort of backdoors as disgruntled employees or industrial spies? Because of this contest and the Underhanded C Contests, we have two corpuses of backdoored code. However, I’m not aware of any corpus of deployed backdoor code which we could compare.

So anyway, I look forward to seeing this game at Defcon, and in the future, more serious games for information security.

Previously, I’ve blogged about the Underhanded C contest here and here

SOUPS Keynote & Slides

Posted on by

This week, the annual Symposium on Usable Privacy and Security (SOUPS) is being held on the Microsoft campus. I delivered a keynote, entitled “Engineers Are People Too:”

In “Engineers Are People, Too” Adam Shostack will address an often invisible link in the chain between research on usable security and privacy and delivering that usability: the engineer. All too often, engineers are assumed to have infinite time and skills for usability testing and iteration. They have time to read papers, adapt research ideas to the specifics of their product, and still ship cool new features. This talk will bring together lessons from enabling Microsoft’s thousands of engineers to threat modeling effectively, share some new approaches to engineering security usability, and propose new directions for research.

A fair number of people have asked for the slides, and they’re here: Engineers Are People Too.

Malware reports? (A bleg)

Posted on by

I’m doing some work that involves seeing what people are saying about the state of malware in 2010, and search terms like “malware report” get a lot of results, they don’t always help me find thinks like the Symantec ISTR, the McAfee threats report or the Microsoft SIR.

To date, I’ve found reports from Cisco, IBM/ISS, Kaspersky, McAfee, Microsoft, Sophos and Symantec. Are there others that cover malware? (I’m leaving off Verizon since it doesn’t cover what I need for this particular project.) Recent things like the Nocebo paper here are also interesting.

If you know of other reports that will help me gain insight into the state of the world, please leave a comment.